Friday, 15 February 2013

The Mortal Engines Project

The last project for Game Production
was a character project based on the book Mortal Engines by Philip
Reeve. The characters we modelled had to be a self portrait in the
style of Mortal Engines. I was excited for this project, I've always
enjoyed reading and thought the Mortal Engines story was fun to read
with plenty of good descriptive writing of various imagery,
especially the characters. I've also always enjoyed reading because
it gives me the opportunity to imagine for myself how a story would
work visually so this projects has given me the opportunity to
develop my ideas into a completed final design with concepts and a 3D
model.

As per usual the project had some
outlined aims and requirements specific to it. Our models needed to
show good appreciation of the final aesthetic, proportion, colour,
silhouette and detail density, and the character models were to be
judged on anatomical accuracy and artistic interpretation as well as
the technical requirements including, an efficient mesh with good
surface topology, that demonstrates an eye for sculpting convincing
body form, muscles and facial structure. As usual our tutor was
looking for an efficient use of textures, conveying the different
surface qualities such as skin, clothing etc.

I was a little concerned
initially considering the time frame that had been given to complete
the project, which included concepting ideas for the character,
including sketches of various different ideas considering the
different character elements from the book, complete with a final
idea and reference drawings from the front, side and back for use
when modelling. As many reference images were then collected in
relation to my final character idea as well as mood boards and colour
palettes. The project then required me to model my high poly version,
unwrap and texture it, I then planned on learning some basic Zbrush
functions to create and bake normal maps and ambient occlusion maps.
My final model then had to be rigged as well as final renders being
taken for presentation purposes. A low poly 'LOD' then had to be
modelled, unwrapped and textured. Considering all of these components
there was an astonishing amount of work to do in the four weeks give
in my opinion, and as you'll find out, I did struggle to complete the
work that I did.

As
mentioned, I started by creating a number of concept sketches and
then a final design for my character. In my final design I decided to
mix various elements from my four concept sketches. With the 'Mortal
Engines' world, I imagined that lots of things would be salvaged to
be used like described in the book when London eats another city. My
final idea was that instead of my Pirate 'me' character having a
plain wooden stump instead of a foot he could have a car piston which
could move when walking. This would add interest to my character
design and would also create a challenging element when it comes to
rigging the character. I also decided to add a mechanical hand on the
same side as the foot, the idea is that my character would've
sustained an injury to that side of his body and had salvaged parts
to repair himself, it also gives the character consistency in the
interest of his appearance. The final designs are shown below;

The
modelling process went quite well, I feel that I am now at a stage
where I am able to model with a reasonable amount of confidence,
knowledge and experience in creating accurate models with clean
geometry. After first creating a base model, with basic anatomy as a
starting point I then began to focus on modelling the head, being as
the project was a 'self portrait' I needed to try and get as close a
likeness to myself as possible within a reasonable amount of time. I
modelled the head using the box modelling method, following the
previous method I used from the gladiator project and the tutorial
from year one. It went well but slower than expected, and I was
having to add lots of loops to increase the geometry meaning I was
constantly going over the same area refining and optimising the
geometry from all view ports. I finally reached a point that I
was happy with, a point were the tweaks I was making were so small it
seemed unnecessary to continue for such small details, again, if the
time frame had been longer it is certainly an area were I would have
continued. I then spent time beginning to add clothes to my body mesh
by extruding out from the centre of the body and reattaching at the
edges to create the jacket. For the pants I have simply rescaled the
legs and added some extra loops where I'd expect there to be more
defined creases such as around the knee area and above the boot. I
also added some twist to individual loops to make the clothing seem
more natural instead of pre-planned. I found that I spent a lot of
time modelling the mechanical hand which was not as easy as I'd
anticipated, especially in terms of how time consuming it was.
Because the mechanical arm/ hand had to be rigged I specifically had
to think and plan about which elements to include, where the hand was
going to bend and where the joints needed to be placed specifically.
Despite this I think the final hand looks great.

Into
the texturing process and I was looking at taking a new approach to
the process. Usually after unwrapping I will do the diffuse texture
first, then go onto the normal map and finally the specular map. This
time I planned to use the baking method to bake my high poly models
(created in Zbrush) onto the mesh to create my normal maps and this
time ambient occlusion maps also. From the baked maps I will then
paint the diffuse maps using the UV coordinates as well as the
information that has been baked in the the normal and AO maps. The
first bake I did was the main body. I decided to do this first as I
was trying to use ZBrush to sculpt various elements especially
creases in the clothing. As I had never used ZBrush before, and
because time for the was short, I decided to stick to the basic tools
of ZBrush and use it purely for creating some defined creases in the
clothes. ZBrush was a little daunting to get my head around but I
managed to develop some simple techniques to get the final effect in
the creased clothes I desired. I decided to import the ZBrush model
back into 3DS Max to bake the normal and Ao maps in that program
instead of using ZBrush's render to texture tool. I was informed by a
third year that this would potentially yield better results because
I'd be baking straight onto my actual model. This is what I did and I
didn't have a chance to experiment with the two options so I cant
conclude if one method is in fact better than another. I also baked
the individual high poly props including the gun and telescope as
individual elements. This just meant that I had to use the mix normal
maps feature in nDo2 to combine the various normals I had baked which
was an easy enough process. This was the same with the individually
baked AO maps but these were just combined easily within Photoshop.

Using
as much as my reference material as possible I created my diffuse
texture maps. I also tried to texture my model to resemble my initial
concept paintings as closely as possible. This meant that for a lot
of elements, particularly the clothing I had to work quite hard in
manipulating various reference images to get the desired final
effect, including merging various colours, patterns, textures, and
other things such as stains etc. For the mechanical hand and foot I
used some good metal texture reference images I had gathered but when
applied to the model it looked quite plain. I decided to also overlay
a rust texture which I had taken myself last year which I then
painted out in areas to show rust in the desired way, such as in the
joints etc. I was quite disappointed, and a little annoyed at how my
reference images for my head had come out. They appeared to be very
low resolution and not a particularly good quality, even worse when
they were stretched to fit my UV's. In the end I realised that my
camera had been set to manual focus instead of automatic which was a
silly mistake. Fortunately the lower quality reference images seemed
to lend themselves well to the model as the skin tone looked much
better. The final texture that needed to be done was the specular.
This time I decided to try out a colour specular map which was to be
placed both in the Specular Level and Specular Colour map slots
within 3DS Max. They were quite easy to prepare as from what I can
understand it is simply manipulating the diffuse maps to get the
desired effect. I did this by changing the hue/ saturation/ lightness
adjustments as well as slightly changing the levels when needed. The
only major change to colour was in the skin tone. From a tutorial I
followed it showed that the skin tone within a specular map should
have a darker blue tone to it and this seemed to work well on the
models.

Once
the model was finished I hadn’t left myself much time at all to
complete the rigging. Fortunately I have now rigged a few models,
from the gladiator project to the texturing competition last year,
and once I had picked up the tools and functions of the skin modifier
I was fairly comfortable with getting a basic but solid rig.
Unfortunately that was a long time ago and my mind needed refreshing
somewhat, particularly with the method of setting up the biped
correctly and the specific tools and how to use them properly and
efficiently within the skin modifier. Once I had everything set up
properly though I began to remember quite quickly and followed a
method I used last time for getting a nice clean rig. The method
includes attaching verts in the centre of bones a full 1 and verts
either side of a joint at a 0.6/0.4 or 0.7/0.3 respectively and then
try to follow a steady gradient of weights. I then use the animation
I've set up with the biped to change any verts weights independently
that look out of place.

With
hardly any time left to complete the project I tried my very best to
try and optimise my model to a low poly LOD. The aim was to do a 2000
tri low poly model but after many hours refining and adjusting I was
able to pull the model down to roughly 2,700 tris which is really
still a way off from the initial aim, but, considering the high poly
tri count really isn't bad. I also attempted a diffuse bake onto the
low poly model, which was a really rushed job, it hasn't come out too
bad in all honesty but I know I could do a much better job if I had
more time to spend on it.

There
are many positives about the final outcome of this project. The main
one being that I am extremely happy with the final model as a whole,
I think it presents a very interesting character, with a good colour
palette which is consistent throughout yet diverse in its
presentation.

I
am happy with learning some basic uses of ZBrush which has given me a
good stepping stone towards better normal map creation and although
I’ve already been familiar with baking I think this project has
helped develop my skills in this area.

I dont know what more I
can say in regards to the time given for this project other than to
say I have struggled to get the work done in time. I have tried to
balance a quick and efficient work flow whilst still trying to
achieve a high standard of work but until you begin the different
aspects of the whole process you don’t realise how much time each
aspect is capable of consuming. This has been a hard but valuable
lesson to learn.

Final renders taken in Marmoset Toolbag

Final renders taken in 3DS Max 2012, showing the final model with normal maps and Ao maps applied.